Time control safety lock for a safe or the like with indicating means outside the safe for indicating the time control of the lock

ABSTRACT

Time control safety lock for a safe or the like in which a blocking member is withdrawn by a clockwork mechanism during a predetermined time period out of the path of a locking member to permit opening of the safe only after elapse of said predetermined time period, and in which signalling means observable at a location outside the safe are provided to indicate the presence of the time controlled blocking member and preferably also the time period this blocking member will still remain in blocking position.

United States Patent [1 1 Heinemann et al.

[451 Sept. 17, 1974 1 TIME CONTROL SAFETY LOCK FOR A SAFE OR THE LIKEWITH INDICATING MEANS OUTSIDE THE SAFE FOR INDICATING THE TIME CONTROLOF THE LOCK [75] Inventors: Albert Heinemann, Scherzingen;

Wilhelm Opferkuch, Freiburg, both of Germany [73] Assignee: TheodoreKromer KG, Freiburg/Br.,

Germany [22] Filed: Oct. 18, 1972 [21] Appl. No.: 298,786

[30] Foreign Application Priority Data Oct, 20, 1971 Germany 2152221[52] US. Cl 70/271, 70/273, 70/432 [51] Int. Cl E051) 43/00 [58] Fieldof Search 70/267, 268, 269, 270,

70/271, 272, 273, 266, 432; 116/2, 4, 6; 340/282, 177 VA; 58/152 H 5 6]References Cited UNITED STATES PATENTS 665,374 1/1901 Stockwell 70/273717,477 12/1902 Walther 340/282 X 925,900 6/1909 Hansen l 70/267 X1,164,378 12/1915 Miller 70/270 X 2,561,512 7/1951 Holmes et a1. 235/92DN UX 2,772,411 10/1966 Cooper 340/282 3,227,863 1/1966 Winsor 340/282UX 3,509,527 4/1970 Oukcs ct a1. 340/282 X 3,643,420 2/1972 Haydon 1.58/25 X Primary Examiner-Robert L. Wolfe Assistant Examiner-Richard P.Tremblay Attorney, Agent, or Firm-Michael S. Striker 5 7 ABSTRACT Timecontrol safety lock for a safe or the like in which a blocking member iswithdrawn by a clockwork mechanism during a predetermined time periodout of the path of a locking member to permit opening of the safe onlyafter elapse of said predetermined time period, and in which signallingmeans observable at a location outside the safe are provided to indicatethe presence of the time controlled blocking member and preferably alsothe time period this blocking member will still remain in blockingposition.

13 Claims, 8 Drawing Figures PAIENIEBSEPITBH 3.835.619

SHEET 1 0F 6 FIG] PATENIL SEPI 11974 SHEEI 2 B 6 mdE 9.3 mm, 0? 1m 74:ET 5rd 3 v NOE PAIENIED m" 1835.679

' sum 3 or 6 FIG. 4

PATENTEDSEP 1 mm SHEEI 5 0F 6 FIGJS TIME CONTROL SAFETY LOCK FOR A SAFEOR THE LIKE WITH INDICATING MEANS OUTSIDE THE SAFE FOR INDICATING THETIME CONTROL OF THE LOCK BACKGROUND OF THE INVENTION This inventionrelates to a time-controlled safety lock containing at least oneclockwork mechanism for withdrawing a blocking member or for unblockingthe path of a locking or like element at a preselectable time.

Time-controlled safety locks for securing the doors of steel safes, bankstrong rooms and the like are well known in the art. Generally suchtime-controlled locks contain at least two or more clockwork mechanismsof which only one is actually needed for controlling a blockingmechanism, whereas the others are merely duplicates which are availablein the event of failure of one of the clockwork mechanisms. Thesetimecontrolled locks are affixed to the inside of the door they secureand they cannot be seen or operated from the outside when the door isclosed.

In the case of doors secured by conventional locks of this type it istherefore impossible by external inspection to establish the presence ofa time-controlled lock for blocking the door until the expiry of apreset period. This has the drawback that in the event of a raid theonly way a person holding the keys can demonstrate the presence of atime-controlled lock is to open the main locks and to show the burglarsthat this fails to open the locking mechanism of the door. If the personattempting the robbery is not convinced by this evidence the threatenedperson holding the keys may be in considerable danger.

SUMMARY OF THE INVENTION For this reason it is the object of the presentinvention to provide a time-controlled lock of the abovespecified kindwhich eliminates the above-described risk.

To attain this object the present invention provides a time-controlledlock of the specified kind which in a visible position on the outside ofthe door secured by such a lock comprises an optical and/or acousticindicating device associated with the clockwork mechanism or mechanismsof the time-controlled lock, or directly or indirectly driven thereby,for disclosing the presence and the blocking of the lock and forindicating at least the final part of the time remaining to theunblocking of the lock. This arrangement enables a would-be burglar tosee for himself that the door is secured by a time-controlled lock thatcannot be interfered with from the outside until the indicated time haselapsed. This is more likely to persuade him to abandon the raid.

It may be useful to provide a blocking member which during the lapse ofa preset blocking time is slowly withdrawable by the one or moreclockwork mechanisms into an'unblocking position in which it permits alocking element, bolt or the like associated with the locking mechanismof the lock to be withdrawn, and which cooperates with setting means ofa measuring potentiometer incorporated in the electrical circuit of anindicating instrument, preferably in the form of an ammeter. This simplearrangement permits the passage of time to be represented by the changein current due to the change in potentiometer setting and to beindicated by the ammeter. The scale of the measuring instrument may becalibrated in units of time, preferably in hours. In a preferredembodiment the blocking member may have an extension in the form of arack which meshes with the setting pinion of the measuringpotentiometer. In a modified form of construction a shift bar cooperateswith the clockwork mechanisms and is provided along part of its lengthor in the form of an extension with a rack for driving the settingpinion of a measuring potentiometer in the energizing circuit of anindicating instrument. In these embodiments only that part of theblocking time is actually indicated, during which the clockworkmechanisms are in engagement with the shift bar. This part may comprisethe final ten hours of the total blocking time which may be up to hours.Any one of these embodiments will therefore either indicate to awould-be burglar that more than 10 hours must still elapse before thelock is unblocked or, if this time is less than ten hours, theinstrument will indicate the time that remains before the lock isunblocked.

In yet another arrangement the output shaft of at least one of theclockwork mechanisms may be directly or indirectly coupled for instanceby means of the gearwheel under the clock dial with a measuringpotentiometer or the like incorporated in the electrical circuit of anammeter or similar indicating instrument. In such an arrangement theentire time lock will continue to be blocked at any particular momentcan be shown. Moreover, this latter arrangement affords the possibilityof re-checking the selected blocking time when the timecontrolled lockhas been set.

In an alternative arrangement the blocking member is provided with asliding contact or associated with a rotary multi-position contact forcooperation with a plurality of fixed contacts for consecutively closingcircuits through a plurality of associated signal lamps or the likewhich are thus made to light up in succession for indicating the passageof time to the end of the blocking period. The width of the slidingsurface on the moving contact may be sufficient to enable it to completethe circuits of two neighboring signal lamps at the same time when it isin an intermediate position between two consecutive fixed contacts, twoneighboring lamps glowing simultaneously indicating an intermediatetime. For example, if each signal lamp lights up at the full hour, thelighting up of two neighboring lamps simultaneously would indicate thehalf hour. In another modification the several contacts may be connectedto a difference counter preferably capable of counting forwardly andrearwardly. For instance, this difference counter could be adjusted tothe full hours when the blocking time is being preset, the counter thencounting down the hours to zero. For counting only the last part of theblocking-times a relatively simple counter could be used showing onedigit only.

Instead of an optical indicating means, or in addition thereto, at leastone microphone may be provided adjacent the clockwork mechanism andconnected to a loudspeaker outside the safe to transmit the noise of theclockwork mechanism to the outside. Any wouldbe burglar may well beimpressed and convinced of the presence of a time-controlled safety lockif he can actually hear the clocks ticking.

In order to use the batteries for running these indicating devices assparingly as possible it is desirable to provide the electricallyoperated indicating instrument with a switch so that the instrument willwork only when it has been turned on by the switch. This means that theindicating instruments need not operate during the greater part of theperiod the lock remains blocked, and that the batteries will not be usedduring this part of the period. For a check at any time the switch canbe operated and the instrument read.

Moreover, in a preferred arrangement the electrical circuits for anoptical and/or acoustic indication of the running down of the clockworkmechanisms, which could incidentally be electrical clockwork mechanisms,may be optionally connectableto the mains or to batteries in such a waythat a relay brings in the battery supply when the mains supply is cutoff. Such an arrangement prevents failure of the lock as a result offailure of the power supply, even if normally the lock relies on themains, and it is thus possible to make use of electrically drivenclockwork mechanisms.

In time-controlled safety locks containing withdrawable blocking membersonly a minor fraction of the blocking member projects, during the lastpart of the blocking period, into the path of the element the blockingmember is intended to block. This may permit the lock to be opened byusing some force before the blocking period has completely expired. Itis, therefore, an incidental object of the present invention so toconstruct the time-controlled lock and the associated indicating meansthat the above-described risk is eliminated.

This development of the invention, which is considered to possessparticular merit, consists in that the withdrawal of the blocking memberin opening direc tion proceeds at a uniform rate until shortly beforethe blocking time is due to expire and then at a higher rate to the endof the blocking period.

If the blocking member is arranged to be withdrawn at a higher rateduring the final hour of the blocking period, then the availabledistance for the withdrawal of the blocking member during this finalhour has to be correspondingly longer. Accordingly the distancetraversed even during a final half hour has to exceed the distancetraversed by the blocking member in the same period if its rate ofwithdrawal had remained unchanged. The blocking member will thereforealso project a longer distance into the blocked path than when its rateof withdrawal is uniform.

Such differences in the rate of withdrawal of the blocking member can begenerated with the aid of a uniformly running clockwork mechanism by theinterposition of suitable transmission means. A suitable embodiment ofsuch a mechanism is one in which the displacement of a shift rodeffected by the clockwork mechanisms is used to deflect at least oneswing arm, a further transmission arm fast on the pivot pin to which theswing arm is affixed being coupled by a slot and pin coupling to a thirdlever arm adapted to withdraw the blocking member, the slot beingprovided on one arm and the pin on the other arm, and the slot having acurvature which with due regard to the lever motions and lever ratiosimparts a uniform rate of displacement to the blocking member during themajor part of its withdrawal, whereas the slot contains an abrupt changein its angle of inclination adapted to impart an accelerated rate ofdisplacement to the blocking member during the latter part of itsmotion, with the operation of the indicating instrument at acorrespondingly higher rate. The total path length of the withdrawingblocking member need not be longer than in a lock lacking the two-ratewithdrawal feature. The path length provided up to the beginning of thefinal period can be slighly reduced to make a longer path available forthe final period before the unblocking of the lock, this longer pathbeing traversed accordingly at a higher rate.

Accordingly the scale indicating the final period may also be lengthenedor the number of lamps indicating this final period may be increased,thereby providing a finer subdivision of the time scale in this region.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the folling description of specific embodimentswhen read in connection with the accompanying drawings.

- BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general view of atime-controlled safety lock according to the invention;

FIG. 2 is a section on the line IIII of FIG. 1;

FIG. 3 is a cross section normal to the section shown in FIG. 2;

FIG. 4 is a schematic representation showing the association of ablocking member in the time-controlled lock with a measuringpotentiometer, and the method of transmitting the potentiometer signalto an indicating instrument; v

FIG. 5 is a modified form of construction in which a sliding contact isconnected to the blocking member;

FIG. 6 is a section of the indicating instrument associated with theembodiment comprising a sliding contact and a number. of signal lamps;

FIG. 7 is a view of the indicating instrument in FIG. 6; and

FIG. 8 is awiring diagram of the indicating instrument shown in FIGS. 5to 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1 atime-controlled lock generally indicated by reference number 1 containsthree mechanical clockwork mechanisms 3 in a casing 2, two of saidclockwork mechanisms being merely provided as a precaution against thepossibility of failure of one of the clockwork mechanisms.

In a manner which as such is known in the art these clockwork mechanisms3 have clockwork driven dials 4 which perform a complete revolutionwithin a specific period of time. Embodiments which have proved usefulhave dials which revolve once in hours, and which thus permit a sequenceof consecutive nonworking days to be bridged. These dials can be presetto a desired period of time, the setting operation simultaneouslywinding the clockwork mechanism for this period.

In a conventional manner the rotating dials 4 carry pins 5 or the likewhich at the end of a given period of time each engage a tooth 6 on ashift bar 7.

From the time of engagement onwards and for the remainder of the presettime the shift bar 7 will therefore move. The shift bar 7 transfers itsmovement, in a manner as will be described later, to a blocking member 8which is thereby gradually withdrawn from an opening 9 into which a pin10 connected to the mechanism of the main locking system must bereceived for unlocking the door. Since the pin 10 cannot fully enterthis opening 9 until the blocking member 8 has been completely withdrawnin the direction indicated by an arrow Pf 1, the time-controlled lockremains locked and cannot be unlocked until the preset blocking time haselapsed.

The proposal made by the invention consists in externally clearlydisclosing the presence of the timing device by indicating at least thatpart of the time during which the blocking member is being withdrawn.

In the embodiment according to FIG. 4 the blocking member 8 carries arack 1 1 which extends in the direction of withdrawal of the blockingmember, and which meshes with a pinion 12 mounted on the setting shaft13 of a potentiometer 14. This potentiometer is included in theelectrical circuit of an ammeter 15 and the current flowing in thiscircuit will therefore gradually vary as the setting shaft of thepotentiometer 14 turns. The scale 16 of the ammeter 15 may be graduatedin hours to permit at least the last part of the period the lockcontinues to be blocked to be read. The pointer 17 of the ammeter 15 maygive the reading at the extreme end 16a of the scale 16 before the shiftbar 7 begins to withdraw the blocking member 8, thus indicating that thelock cannot be unlocked for a period exceeding say 10 hours.

It will also be understood from FIG. 4 that the final hour occupies aportion of the scale 16 which is about twice as long as that of theother hours. It will be later described how a correspondingly more rapidwithdrawal of the blocking member by a longer distance in the finalperiod is effected.

A different embodiment is illustrated in FIGS. 5 to 8. In this examplethe blocking member 8 carries a sliding contact 18 which in course ofthe withdrawal of the blocking member in the direction of arrow Pf 1consecutively rides over a sequence of fixed contacts 19 and therebyconsecutively closes the electrical circuits of signal lamps 20, asschematically illustrated in detail in FIG. 8. The current source ispresumed to be a battery 21. The several signal lamps in FIGS. 7 and 8may be arranged to indicate the last ten hours of the period thetime-controlled lock remains blocked.

FIG. 8 shows a switch 22 in the main circuit of these signal lamps 20which, as a rule, is kept open. The circuit of the battery 21 is thenordinarily without current, energy of the battery 21 is saved and noneof the signal lamps is operating. At the moment the switch 22 is closed,however, it reveals the presence of a timecontrolled lock and alsoindicates as to when the locking time will expire. In this embodimentthere is provided according to FIGS. 6 and 7 a central press button 23for actuating the switch 22, said press button closing the switch 22when being depressed, e.g., against the force exerted by a spring, andopening said switch when being released.

In a similar manner the embodiment according to FIG. 4 may comprise,too, a switch for closing the circuit of the ammeter 15 so that also inthis arrangement the batteries provided as energy sources are not used.Moreover, the embodiment according to FIG. 4 may comprise as anadditional indicating element a signal lamp 24 which indicates that thetime controlled lock is still blocked.

In the embodiment according to FIGS. 5 to 8 an additional signal lampmay be provided to indicate the time preceding the last 10 hours of thepreset blocking period.

In a different form of construction, not shown in the drawings, it wouldbe feasible for instance directly to couple the rotating dial 4 of oneof the clockwork mechanisms 3 with a measuring potentiometer of thelike, and the passage of time could then be indicated on a scale in muchthe same way as in FIG. 4. The provision of mechanical transmissionmeans from the clockwork mechanisms 3 to an indicating instrumentprovided with a calibrated scale would also be possible. However, atransmission through electrical circuits has the major advantage that noconclusions can be drawn from the position of the indicating instrumentwhere the time-controlled lock is in fact situated in the closed door.Also, electrical transmission is simpler.

As already mentioned in the description of the illustrated embodimentsit is proposed to move the blocking member more rapidly during the finalstage of its withdrawal so that it travels a longer distance during thistime. This is indicated by the lengthening of the scale 16 in FIG. 4 andby the provision of a larger number of signal lamps 20 for indicatingthe last hour of the blocking period in the embodiment according toFIGS. 7 and 8. The object of this arrangement is to ensure that theblocking member 8 will still project sufficiently far into the opening 9to prevent the pin 10 from entering at a time immediately preceding thepreset end of the blocking period. If the rate of withdrawal of theblocking member 8 were uniform, the pin 10 could be forced into theopening shortly before the end of the blocking period, since theblocking member 8 would at this time project very little in the path ofthe locking member 10. The increased rate of withdrawal substantiallyeliminates such a possibility. A time-controlled lock thus designed istherefore very much safer and a would-be safebreaker may as well bewarned that the time for opening the safety lock is approaching.

It will be understood, principally by reference to FIG. 1, how adifferential rate of withdrawal of the blocking member 8 is achieveddespite the uniform speed of the clockwork mechanisms 3.

The shift bar 7 in this arrangement operates two swing arms 25 and 26.An additional transmission arm 28 is fast on the pivot pin 27 to whichthe arm 26 is affixed. The transmission arm 28 is coupled by a pin andslot coupling in a manner yet to be described to a lever arm 29 whichengages the blocking member for displacing the same. The slot 30 isprovided on one of the arms and the cooperating pin 31 on the other. Inthe described embodiment the slot 30 is formed in a widened part of thetransmission arm 28, whereas the cooperating pin 31 is fitted to thelever arm 29. When the transmission arm 28 is deflected in the directionindicated by an arrow Pf 2, the lever arm 29 is forced to swing in thedirection indicated by an arrow Pf 3 by virtue of the curvature of theslot 30. The slot thus brings about the withdrawal of the blockingmember 8 in the direction of arrow Pf 1 since the free rounded end 29aof the lever arm 29 is received intoa corresponding socket 32 in theblocking member 8. The portion of the slot 30 along which the pin 31initially slides has a curvature which with due regard to the leverratios causes a substantially uniform displacement of the blockingmember during the greater portion of its time of with drawal. However,in the final part of the withdrawing motion the slot 30 is abruptlyoff-angled at 33 and this part of the slot causes the pin 31 to be farmore quickly displaced than before, although the angular speed of thetransmission arm 28 is unchanged. The slightly more inclined portion ofthe slot 30 for the reception of the pin after the latter has passedthrough the offangled portion at 33 merely serves for the accommodationof the overrun of the clockwork mechanisms after the end of the blockingperiod.

It will be seen by referring to FIG. 1 that the slot 30 is locatedbetween the fulcrum 34 of the lever arm 29 and its point of engagementwith the blocking member 8 and that from its beginning at 30a, where thepin is situated at the start of the period of withdrawal, the slotslightly reduces its radial distance from the boss 35 of thetransmission arm 28 on the pivot pin 27, towards which the blockingmember is withdrawable. It is also apparent that the off-angled portionat 33 in the slot offsets the slot towards the boss of the transmissionarm. The desired effect is thus achieved with a minimum of mechanicalmeans, the blocking member being withdrawn at a slow uniform rate duringthe major portion of its motion and then at a much more rapid rateduring the final hour or some other part of the blocking period.

In the embodiment according to FIG. 4 the rate of withdrawal of theblocking member during the final part of the blocking period is twicethat during the preceding period of displacement. In the embodimentaccording to FIG. 7 an even higher rate of displacement during the finalpart of the blocking period is provided.

In a desirable manner this additional safety feature of thetime-controlled lock can also be recognized by an intruder who may thusbe persuaded that an attempt on the lock shortly before the end of itsblocking time would also be fruitless.

FIG. 1 also shows gearwheels 4a below the rotating setting dials 4 andthat these gearwheels are adjustable by pinions 4b and which they are inmesh for simultaneously presetting and winding the clockworks.

lt will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types oftime controlled safety locks differing from the types described above.

While the invention has been illustrated and described as embodied in atime controlled safety lock with indicating means indicating the timethe lock remains blocked, it is not intended to be limited to thedetails shown, since various modifications and structural changes may bemade without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. A time controlled safety lock comprising a locking member for lockingthe door of a safe or the like and adapted to be withdrawn along apredetermined path for permitting opening of the door; a blocking membermovable between a blocking position located in the path of said lockingmember to prevent withdrawal of the latter and an unblocking positioncompletely withdrawn out of said path; at least one clockwork mechanismcooperating with said blocking member for moving the latter within apredetermined time from said blocking to said unblocking position; andindicating means cooperating with said clockwork mechanism fordisclosing at a location outside the door the time controlled blockingof the lock and also the final part of the time said blocking memberwill remain in said blocking position, said indicating means includingan electrical instrument and a measuring potentiometer in circuit withsaid electrical instrument and having setting means, and coupling meansfor coupling said setting means of said potentiometer with said blockingmeans for movement therewith.

2. A time controlled safety lock as defined in claim 1, wherein saidelectrical instrument is an ammeter.

3. A time controlled safety lock as defined in claim 1, wherein saidindicating instrument has a graduated scale calibrated in units of time,such as hours.

4. A time controlled safety lock as defined in claim 1, wherein saidcoupling means comprise a rack fixed to said blocking member formovement therewith and a pinion meshing with said rack and cooperatingwith said setting means of said potentiometer.

5. A time controlled safety lock as defined in claim 1, wherein saidcoupling means comprise a shift bar moved in substantially longitudinaldirection by said clockwork mechanism and provided along part of itslength with a rack and a pinion meshing with said rack and cooperatingwith said setting mechanism of said potentiometer.

6. A time controlled safety lock comprising a locking member for lockingthe door of a safe or the like and adapted to be withdrawn along apredetermined path for permitting opening of the door; a blocking membermovable between a blocking position located in the path of said lockingmember to prevent withdrawal of the latter and an unblocking positioncompletely withdrawn out of said path; at least one clockwork mechanismcooperating with said blocking member for moving the latter within apredetermined time from said blocking to said unblocking positions;transmission means between said clockwork mechanism and said blockingmember for moving said blocking member during a first part of saidpredetermined time period at a uniform rate towards said unblockingposition and then at a higher rate during the remaining part of saidpredetermined time period; and indicating means cooperating with saidblocking member for disclosing at I a location outside the door the timecontrolled blocking of the lock.

7. A time controlled safety lock as defined in claim 6, wherein saidtransmission means comprises a shift bar operatively connected to saidclockwork mechanism to be moved thereby substantially in longitudinaldirection, a swing member pivotably connected at one end to said shiftbar and fixed at the other end to a pivot pin, a transmission arm fixedat one end to said pivot pin, a lever arm pivoted at one end andoperatively connected at the other end to said blocking member, and apin and slot connection between said arms and comprising a slot in oneof said arms and a pin fixed to the other arm and extending through saidslot, said slot having a first portion of a curvature so as to impart auniform rate of withdrawal to said locking member during a major part ofsaid predetermined time period and a second portion abruptly deviatingfrom the curvature of said first portion to impart an accelerated rateof withdrawal to said blocking member during the latter part of itsmotion, which thus operates said indicating means at a correspondinghigher rate.

8. A time controlled safety lock as defined in claim 7, wherein said pinand slot connection is located between said one and the other end ofsaid lever arm, wherein said blocking member has one end which in saidblocking position is spaced further from said pivot pin then in saidunblocking position and wherein said second portion of said slot iscurved further in the direction towards said pivot pin than said firstslot portion.

9. A time controlled safety lock as defined in claim 6, wherein saidindicating means comprises an indicating instrument having a pointermoved in correspondence with the movement of said locking member and ascale cooperating with said pointer, said scale being lengthened at thelast part thereof in correspondence with the accelerated rate ofwithdrawal of said locking member.

10. A time controlled safety lock as defined in claim 6, wherein saidindicating means comprises a series of equally spaced signal lamps andcontact means cooperating with said blocking member for energizing saidsignal lamps in succession in dependence of position of said blockingmember, and an indicia at each of said signal lamps indicatingrespectively the time the lock will remain blocked, the indicia of thelast few signal lamps indicating shorter time periods than the precedinglamps of said series of equally spaced lamps.

11. A time controlled safety lock comprising a locking member forlocking the door of a safe or the like and adapted to be withdrawn alonga predetermined path of permitting opening of the door; a blockingmember movable between a blocking position located in the path of saidlocking member to prevent withdrawal of the latter and an unblockingposition completely withdrawn out of said path; at least one clockworkmechanism cooperating with said blocking member for moving the latterwithin a predetermined time from said blocking to said unblockingposition; and indicating means cooperating with said clockwork mechanismfor disclosing at a location outside the door the time controlledblocking of the lock, said indicating means including a plurality ofsignal lamps and including contact means cooperating with said blockingmember for energizing said signal lamps in succession in dependence onthe position of said blocking member.

12. A time controlled safety lock as defined in claim 11, wherein saidcontact means comprise a sliding contact connected to said blockingmember for movement therewith and a plurality of spaced stationarycontacts respectively in circuit with said signal lamps.

13. A time controlled safety lock comprising a locking member forlocking the door of a safe or the like and adapted to be withdrawn alonga predetermined path for permitting opening of the door; a blockingmember movable between a blocking position located in the path of saidlocking member to prevent with drawal of the latter and an unblockingposition completely withdrawn out of said path; at least one clockworkmechanism cooperating with said blocking member for moving the latterwithin a predetermined time from said blocking to said unblockingposition; and indicating means cooperating with said clockwork mechanismfor disclosing at a location outside the door the time controlledblocking of the lock, said indicating means including an electricalinstrument and including a switch for activating and deactivating saidelectrical instrument.

1. A time controlled safety lock comprising a locking member for lockingthe door of a safe or the like and adapted to be withdrawn along apredetermined path for permitting opening of the door; a blocking membermovable between a blocking position located in the path of said lockingmember to prevent withdrawal of the latter and an unblocking positioncompletely withdrawn out of said path; at least one clockwork mechanismcooperating with said blocking member for moving the latter within apredetermined time from said blocking to said unblocking position; andindicating means cooperating with said clockwork mechanism fordisclosing at a location outside the door the time controlled blockingof the lock and also the final part of the time said blocking memberwill remain in said blocking position, said indicating means includingan electrical instrument and a measuring potentiometer in circuit withsaid electrical instrument and having setting means, and coupling meansfor coupling said setting means of said potentiometer with said blockingmeans for movement therewith.
 2. A time controlled safety lock asdefined in claim 1, wherein said electrical instrument is an ammeter. 3.A time controlled safety lock as defined in claim 1, wherein saidindicating instrument has a graduated scale calibrated in units of time,such as hours.
 4. A time controlled safety lock as defined in claim 1,wherein said coupling means comprise a rack fixed to said blockingmember for movement therewith and a pinion meshing with said rack andcooperating with said setting means of said potentiometer.
 5. A timecontrolled safety lock as defined in claim 1, wherein said couplingmeans comprise a shift bar moved in substantially longitudinal directionby said clockwork mechanism and provided along part of its length with arack and a pinion meshing with said rack and cooperating with saidsetting mechanism of said potentiometer.
 6. A time controlled safetylock comprising a locking member for locking the door of a safe or thelike and adapted to be withdrawn along a predetermined path forpermitting opening of the door; a blocking member movable between ablocking position located in the path of said locking member to preventwithdrawal of the latter and an unblocking position completely withdrawnout of said path; at least one clockwork mechanism cooperating with saidblocking member for moving the latter within a predetermined time fromsaid blocking to said unblocking positions; transmission means betweensaid clockwork mechanism and said blocking member for moving saidblocking member during a first part of said predetermined time period ata uniform rate towards said unblocking position and then at a higherrate during the remaining part of said predetermined time period; andindicating means cooperating with said blocking member for disclosing ata location outside the door the time controlled blocking of the lock. 7.A time controlled safety lock as defined in claim 6, wherein saidtransmission means comprises a shiFt bar operatively connected to saidclockwork mechanism to be moved thereby substantially in longitudinaldirection, a swing member pivotably connected at one end to said shiftbar and fixed at the other end to a pivot pin, a transmission arm fixedat one end to said pivot pin, a lever arm pivoted at one end andoperatively connected at the other end to said blocking member, and apin and slot connection between said arms and comprising a slot in oneof said arms and a pin fixed to the other arm and extending through saidslot, said slot having a first portion of a curvature so as to impart auniform rate of withdrawal to said locking member during a major part ofsaid predetermined time period and a second portion abruptly deviatingfrom the curvature of said first portion to impart an accelerated rateof withdrawal to said blocking member during the latter part of itsmotion, which thus operates said indicating means at a correspondinghigher rate.
 8. A time controlled safety lock as defined in claim 7,wherein said pin and slot connection is located between said one and theother end of said lever arm, wherein said blocking member has one endwhich in said blocking position is spaced further from said pivot pinthen in said unblocking position and wherein said second portion of saidslot is curved further in the direction towards said pivot pin than saidfirst slot portion.
 9. A time controlled safety lock as defined in claim6, wherein said indicating means comprises an indicating instrumenthaving a pointer moved in correspondence with the movement of saidlocking member and a scale cooperating with said pointer, said scalebeing lengthened at the last part thereof in correspondence with theaccelerated rate of withdrawal of said locking member.
 10. A timecontrolled safety lock as defined in claim 6, wherein said indicatingmeans comprises a series of equally spaced signal lamps and contactmeans cooperating with said blocking member for energizing said signallamps in succession in dependence of position of said blocking member,and an indicia at each of said signal lamps indicating respectively thetime the lock will remain blocked, the indicia of the last few signallamps indicating shorter time periods than the preceding lamps of saidseries of equally spaced lamps.
 11. A time controlled safety lockcomprising a locking member for locking the door of a safe or the likeand adapted to be withdrawn along a predetermined path of permittingopening of the door; a blocking member movable between a blockingposition located in the path of said locking member to preventwithdrawal of the latter and an unblocking position completely withdrawnout of said path; at least one clockwork mechanism cooperating with saidblocking member for moving the latter within a predetermined time fromsaid blocking to said unblocking position; and indicating meanscooperating with said clockwork mechanism for disclosing at a locationoutside the door the time controlled blocking of the lock, saidindicating means including a plurality of signal lamps and includingcontact means cooperating with said blocking member for energizing saidsignal lamps in succession in dependence on the position of saidblocking member.
 12. A time controlled safety lock as defined in claim11, wherein said contact means comprise a sliding contact connected tosaid blocking member for movement therewith and a plurality of spacedstationary contacts respectively in circuit with said signal lamps. 13.A time controlled safety lock comprising a locking member for lockingthe door of a safe or the like and adapted to be withdrawn along apredetermined path for permitting opening of the door; a blocking membermovable between a blocking position located in the path of said lockingmember to prevent withdrawal of the latter and an unblocking positioncompletely withdrawn out of said path; at least one clockwork mechanismcooperating with said blocking member for moving the latter within apredetermined time from said blocking to said unblocking position; andindicating means cooperating with said clockwork mechanism fordisclosing at a location outside the door the time controlled blockingof the lock, said indicating means including an electrical instrumentand including a switch for activating and deactivating said electricalinstrument.